The court heard Miss Bi suffered dozens of injuries including multiple broken ribs, a broken jaw and severe bruising - as well as healing fractures from alleged previous attacks. The court heard a weapon similar to a steel rod was used.

Mr Lewis said: 'Matthews beat Miss Bi to death in her own home in a vicious, sustained and prolonged attack.

'Miss Bi was no match physically for the defendant, she was 5ft 1in and just over seven stone.'

Mr Lewis told the court Miss Bi grew up in Nanjing, China, but came to the UK to study when she was just 15.

He said: 'Ms Bi was born in China on April 24, 1992 and was 24 years old at the date of her death.

'She was initially educated in her homeland and when she was about 15 years old she and her brother were sent to the UK for further education.'

But after striking up a relationship with Matthews her university studies fell began to suffer.

Miss Bi's studies started to suffer after she began a relationship with Matthews, it was claimed

Mr Lewis said: 'Her attendance on the course dropped off and she missed some deadlines of written work.

The court heard Matthews had been 'controlling' to Miss Bi (pictured)

'The university decided that she needed to resit the year, and she agreed to that and was told to re-commence her master's studies.'

The court heard Matthews had been 'controlling' to Miss Bi and blamed his attacks on Attention Deficit Hyperactivity Disorder.

Messages between the couple were read to the jury, with one from Matthews saying: 'The thing is see, I have ADHD babe, and when you do these things I ask you not to, it sets off a trigger I can't control.'

In another he told her: 'Stop texting me you worthless piece of s***. You never do anything right.'

The court heard that the day before Miss Bi's death, she had travelled to London to visit a friend who spotted bruising on her face.

Arriving back in Cardiff, Matthews picked Miss Bi up from the train station and took her back to their flat.

The court heard that the day before Miss Bi's death, she had travelled to London to visit a friend who spotted bruising on her face

But the couple allegedly argued after Matthews saw what he believed to be a message on Miss Bi's phone from a dating website.

After he was arrested, Matthews said that he 'felt the need to kick off because she didn't seem to care'.

Reading an analysis from pathologist Dr Ryk James, Mr Lewis said: 'The assault upon her was severe and involved dozens of impacts.